Biofunctional Hydrogels - Biomaterials - page 180

(a) 0 mM RGD (b) 3.0 mM RGD

100 μm

(c) 1.4

1.2

1

0.8

0.6

0.4

0.2

0

PEGDA 0.7 mM 1.5 mM 3 mM TC well

RGD concentration

FIGURE 8.1 Engineering cell adhesion. Synthetic hydrogels generally allow very little cellular interaction (a),
but can be functionalized with peptides, such as the fibronectin-derived RGD sequence to promote extensive cell
adhesion and spreading (b). This effect can be tuned since the degree of cell interaction depends on the concentra-
tion of the RGD peptide within the hydrogel (c). PEG-based hydrogels containing 3 mM RGD permit cell spreading
that is similar to that seen on tissue culture (TC) wells. (Courtesy of Christy Franco, Rice University.)

encourage selective cell binding. As an example, consider engineering a vascular substitute that
must allow the attachment and spreading of endothelial cells (ECs) and smooth muscle cells (SMCs)
while remaining unreactive to circulating blood platelets, which can form dangerous thrombotic
structures upon binding. While RGD would be a good peptide of choice for EC and SMC attach-
ment, it will also react with platelets, and therefore is nonideal. There are, however, other short

TABLE 8.2 Cell Adhesion Peptides

Peptide Source

DELPQLVTLPHPN
LHGPEILDVPST a

Fibronectin

DGEA Collagen

IKVAV Laminin

KQAGDV Fibrinogen

REDV Fibronectin

RGD Fibronectin, collagen, laminin,

vitronectin

VAPG Elastin

YIGSR Laminin

a Commonly referred to as connecting segment 1 (CS1).